Infamous tar pit in northwestern Canada gets clean-up after 73 years

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The $6.8-million project is removing hydrocarbons by heating contaminated soil. These structures move back-and-forth on rails to cover and cook new piles of earth. (Philippe Morin/CBC)
Workers are busy at the Marwell tar pit in Whitehorse, Yukon, cleaning up a 73-year-old mess.

Project manager Paul Inglis says the companies working on site and the territorial government are trying to assuage people’s fears about emissions and contamination as they clean up the sludge.

The tar pit dates back decades, to the construction of the Alaska Highway. An oil refinery closed in 1945 and some waste tar was soon after put into a clay pit.

Over the years the site “became an unofficial dumping ground. We’ve found a lot of tires that people dumped in here, that kind of thing,” says Inglis.

A lot of digging will be required, as the soil is contaminated four metres deep. (Philippe Morin/CBC)
1958 death prompts call for removal

The tar pits are infamous as someone died there in 1958.

According to a historical research project commissioned by the City of Whitehorse and the Yukon government, a man walking through the pit became “trapped in the semi-liquid tars present and died of exposure.”

The report says the coroner at the time “strongly recommended that the oil pool, which has proven to be a hazard to life, be removed by whatever means necessary as soon as possible.‟

Federal and territorial funding for the project was finalized in 2010. The cleanup is funded 70 per cent federally and 30 per cent by the territorial government with a projected budget of $6.8 million.

The site is in the industrial section of Whitehorse and is owned by the Yukon government.

“The levels of contamination are high enough that there’s obligation to clean it up,” said Inglis.

A British Columbia company called Milestone Environmental Contracting is working with an Alberta company called Iron Creek Group Inc. on the remediation work after years of study.

The site, once restored, could be used for commercial or industrial use.

About six workers are on site daily, with digging and moving of earth scheduled to continue until 2020. (Philippe Morin/CBC)
Vapor rises over Whitehorse

Inglis says the cleanup process uses a technique called thermal conduction.

Contaminated soil is heated in a closed space which is hot as an oven. Vapours from the contamination are captured and a closed system without being released into the air.

It’s a system that works a bit like a water pipe for filtration.

“The heat turns any contaminants into a gas. And then it’s collected and pumped into a container, and that burns off all the contaminants that are burned into gas. The exhaust goes through a tank of water and that water pulls out anything that didn’t get burned,” he said.

Contaminated material will be shipped off-site for disposal.

Inglis says some people have been calling Environment Yukon with concerns about contamination.

However he says the vapour rising from the site is safe.

“It’s almost entirely steam,” he said. “The air emissions are not a concern. They’re far below any level for occupational health and safety standards.”.

Even workers on site are not required to wear masks.

A before-and-after comparison shows the soil after it’s been heated and hydrocarbons removed. (Philippe Morin/CBC)
Years of work ahead

About six workers are on site every day now. The work should continue until 2020, including throughout the winter.

After that, Inglis said the site will be monitored for “at least three years to make sure that nothing is moving off-site.”

Related stories from around the North:

Finland: Terrafame mine admits more widespread groundwater contamination, fights stricter environmental rules, Yle News

Russia: What’s the situation at Russia’s nuclear fuel dump in Andreeva Bay?, The Independent Barents Observer

Sweden: Environmentalists praise ruling on nuclear waste site in Sweden, Radio Sweden

United States: America’s most toxic site is in the Alaskan Arctic, Cryopolitics Blog

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Philippe Morin, CBC News

Philippe Morin, CBC News

For more news from Canada visit CBC News.

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